<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8" />
    <title>Document</title>
</head>
<body>
    <form action="" method="get" accept-charset="utf-8">
        <label>用户名：</label>
        <input type="text" name="">
        <label>密码：</label>
        <input type="password" name="">
        <img src="demo01.php" onclick="this.src='demo01.php?id='+Math.random()" alt="" />
        <input type="submit" name="" value="提交">
    </form>
</body>
</html>